caa a22 4500 445384247 CHVBK 20180317143027.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s10021-011-9411-4 doi (NATIONALLICENCE)springer-10.1007/s10021-011-9411-4 Large Greenhouse Gas Emissions from a Temperate Peatland Pasture [Elektronische Daten] [Yit Teh, Whendee Silver, Oliver Sonnentag, Matteo Detto, Maggi Kelly, Dennis Baldocchi] Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH4 emissions reduced in favor of greater CO2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N2O or global warming potential. We report greenhouse gas fluxes (CH4, CO2, N2O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH4 (25.8±1.4mgCH4-Cm−2d−1) and N2O (6.4±0.4mgN2O-Nm−2d−1). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N2O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH4 fluxes were driven by "hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH4 and N2O fluxes contributed to a high overall ecosystem global warming potential (531gCO2-C equivalents m−2y−1), with non-CO2 trace gas fluxes offsetting the atmospheric "cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential. The Author(s), 2011 methane nationallicence nitrous oxide nationallicence carbon dioxide nationallicence global warming potential nationallicence drained temperate peatland nationallicence management nationallicence agricultural conversion nationallicence Sacramento-San Joaquin Delta nationallicence Teh Yit Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, KY16 9 AL, St Andrews, Scotland, UK aut Silver Whendee Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut Sonnentag Oliver Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut Detto Matteo Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut Kelly Maggi Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut Baldocchi Dennis Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut Ecosystems Springer-Verlag 14/2(2011-03-01), 311-325 1432-9840 14:2<311 2011 14 10021 https://doi.org/10.1007/s10021-011-9411-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9411-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Teh Yit Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, KY16 9 AL, St Andrews, Scotland, UK aut NATIONALLICENCE 700 1- Silver Whendee Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut NATIONALLICENCE 700 1- Sonnentag Oliver Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut NATIONALLICENCE 700 1- Detto Matteo Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut NATIONALLICENCE 700 1- Kelly Maggi Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut NATIONALLICENCE 700 1- Baldocchi Dennis Department of Environmental Science, Policy, and Management, University of California, 94702, Berkeley, California, USA aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/2(2011-03-01), 311-325 1432-9840 14:2<311 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer